The Challenger was a computer-generated model; its presence during VOY: "Endgame" was implied by the fact that the name and registry on the model was left over from "Timeless." The Challenger also appeared in the 2001 and 2002Ships of the Line calendars from Pocket Books, although parts of the CGI image were still labeled "Enterprise" and "NCC-1701-D." Like the USS Venture, the ship's name was emblazoned below the registry number on the ventral side of its saucer section. The Venture model was the first to do this. The registry number, NCC-71099, was likely a tribute to the space shuttle orbiter Challenger, OV-099, lost in January 1986.